3.5mm Panel Mount Stereo Jacks Switchcraft 3.5mm Panel Mount Stereo Jacks are available in Locking, Flush Mount, or Compact Rear Mount models and mate with any standard 3.5mm plug. The locking and flush mount models are rated for 5,000 insertions/withdrawals minimum and feature a 3 conductor open circuit with a durable nickel-plated copper housing with high-quality beryllium copper contacts. The flush mount jack's contacts are silver plated. The compact rear mount model features a three-conductor open circuit in a nickel-plated brass housing with nickel-plated brass contacts.